@Grace Mo,
Both of them are probably pretty good investments, but these are very well studied companies and all the currently available information on them is already built into the stock price, so I doubt either is undervalued. You will hear stories about people who bought the right stock at the right time and made a fortune. What you won't hear about are the people who bought the wrong stock and lost out. When buying stocks as an independent investor, you will likely get the best results by buying a basket of decent quality stocks across a number of industries. It's not particularly glorious, but it yields the highest yield for the lowest risk.